Rock-drill.



W. A. SMITH.

ROCK DRILL.

APPLICATION FILED IuLY 2o, I9I2.

Patented July 18, 1916.

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'AEN 'an vc WILLIAM AGUSTVSMITH, OF DENVER, G OLOLRADO, ASSIGNOR OFONE-HALF TO' WILLIAM W. HASSELL, 0F COLORADO SPRINGS, COLORADO.

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specification ofLt'teprs Patent.

Patented July 18, 1916.

Application led July 20, 1912. Serial No. 710,635.

object thereof is to provide an improved and novel construction of rockdrill.

In the drawings: Figure 1 1s a slde elevation of the invention, partlyin section; Fig. y

2 is an enlarged fragmentary sectional view; and Fig. 3 1s a section onthe line 3-3 of Fig. 1.

Cylinder 1 has a large bore 2 and a small bore 3, a piston 4 operatingin the bore 3 and being connected by a pitman 5 to a' crank 6 that ismounted in a crank case 7. A hammer 8 operates in the large bore 2 andhas an extension 9 that is received in the front end of the small bore3. On the backward stroke of the piston 4 a partial vacuum is created inthe space 10 between the adjacent ends of the hammer extension 9 and thepiston 4 which eHects rearward movement of the hammer until the hammer 8closes a port 11 that communicates by means of a passage 12 with theinterior of crank case 7. The closing of port 11 results in compressionof the air between hammer 8 and the inner wall 13 formed by the largebore 2 of the cylinder effecting stoppage of the hammer. At the sametime the piston 4 in its rearward travel uncovers and opens an air inletvalve -14, permitting air to enter the small bore 3.

that communicates with the large bore 2,

causing a breaking of any partial vacuum that may eXist in bore 2. Whenthe eXtension. 9 of hammer 8 moves past an out-- let valve 16 thatcommunicates with bore 3 it permits escape therethrough of the air thathas beenv compressed in space 10 causing the hammer to be freedv offurther pressure. The hammer engages al striking plug 17 and should forany reason the hammer not strike plug 17, the compressed air in cushionchamber 2O stops the blow.

Relief valve 19 does not open on the for.- ward stroke of the hammer butopens when the hammer starts back to relieve any `pOrtion` of the vacuum'in chamber 2O caused by the rearward movement of the hammer, the sameas valve. 15 actson rear end. The valve 19f serves to increase the.inlet'area of chamber 20 rand when 18 is closed at both ends, affordsthe sole means of communication between 18 and 20. Upon the forwardmovement of the piston it creates a partial vacuumin passage 12 whichdraws air from the large bore 2 through port 11 and also from chambers18 and 20vthus assisting in the forward propulsion of the hammer byremoving the resistance that the air'in said chambers wouldy naturallyoffer if present. When piston r4 starts forward it acts to cause airwith a 'rush to be drawn from duet 12 before valve 21 can open for aperiod sulicient to relieve the vacuum. Theinlet area of valve 21 isvery slight, as compared with the piston area, consequently but littleair can pass through same during a certain period. Since the piston 4causes a. sudden pulsation on its forward movement an air valve 21. oncrank case 7 is opened for an instant until hammerr 8 travels forward torelieve the vacuum as above described. The

valve 21 acts to overcome all outlet leaks and soI nectswith anysuitable source of supply by a pipe or hose,lno't shown. Passage 23leads lto a spacer ring 25 which is perforated to allow the water toenter a port`26 that is formed in a rotating sleeve 27. The spacer ring25 is sealed by packing 28 at its ends. Sleeve 127 which is made intwosections has its `inner section` formed with an annular flange 29 thatvrotates in a pocket formed between head 22 and a ring 30 secured intheouter end portion of cylinderl. An adjustling nut 31 threaded into head22 enables the packing to be adjusted as desired. A water pipe 32 isinserted in sleeve 27 and registers with the port 26 therein and iscarried by a taper or cone nut 33 which is threaded into engagement withthe sleeve 27. Pipe 32 is secured to the rotating drill bit 34 b v meansof a 'series of ears 35 formed on drill 34 and bent to engage with saidpipe on its opposite sides to allow of relative free sliding movement ofthe parts.

Since the point of discharge of the water: from the water pipe 32 is atall times directed at the drill 34 during the reciprocation of thelatter, it will be apparent that the hole being drilled will becontinually flooded and consequently washed out, carrying off theproducts that result from the drilling operation.

What is claimed is:

l. The combination with a cylinder having a large bore and a small boreand a crank case forming an extension of the small bore, a piston in thesmall bore, an air inlet valve communicating with the small bore, aninwardly opening air valve on the crank case, a hammer in the large borehaving an extension that operates in the small bore, an inwardly openingrelief valve in the large bore at the juncture between the bores, anoutwardly opening valve between the relief valve and the air inlet valveof the large bore, said cylinder having a passage which communicateswith the crank case and the front end of the hammer, a pair of chambersat the front end o the hammer and a relief valve between said chambers.

2. In combination with a cylinder having a crank case connected thereto,a piston in the cylinder, a hammer actuated by the piston, a reliefvalve in the hammer bore, said cylinder having a passage which connectsthe hammer' bore and crank case, and an inwardly opening valve in thecrank case.

Copies of this patent may be obtained for ve cents 3. In combinationwith a cylinder havmg a crank case connected thereto, a piston inthecylinder, a hammer actuated by the piston, means whereby the hammer iscushioned upon its return stroke, means to break the vacuum in the spacebetween the piston and hammer when the piston reaches the ioned upon itsreturn stroke, means to break the vacuum in the space between the pistonand hammer when the piston reaches the limit of its backward stroke,means whereby a partial vacuum is formed at the front and rear ends ofthe hammer upon movement of the piston on its working stroke,

-and means to allow the air compressed between the hammer and piston toescape when the hammer has completed its working stroke.

In testimony whereof I have hereunto set my hand in presence of twosubscribing witnesses.

WILLIAM AUGUST SMITH.

lVitnesses E. W. Davis, J. H. WILSON.

each, by addressing the Commissioner of Patents,

Washington, D. C.

